The 2DWG meta-database is a searchable database of 2-D electrophoretic gel images found on the Internet. A meta-database contains information about locating data in other databases - but not that data itself. This database was constructed because of a need for an enriched set of World Wide Web (Web) locations (URLs) of 2-D gel images on the Internet. These gel images are used in conjunction with the NCI Flicker Server to manipulate and visually compare 2-D gel images across the Internet. User's gels may also be compared with those in the database. The 2DWG is organized as a spreadsheet table with each gel image being represented by a row sorted by tissue type. Data for each gel includes tissue type, species, cell-line, image URL, database URL, gel protocol, organization URL, image properties, map URL if it exists, etc. The 2DWG may be searched to find relevant subsets of gels. Searching is done using the dbEngine - a Web database search engine which accesses selected rows of gels from the full 2DWG table. The 2DWG meta-database is accessible on the Web at http://www-lecb.ncifcrf.gov/2dwgDB/.